4-bromo-3,3,4,4-tetrafluorobut-1-ene

Endpoint summary

Description of key information

Description of relevant studies: 

NOEL 1000 ppm - Two-week inhalation toxicity study in male rats - Malley, L.A. (2003) - Supporting study.

No effects level not ID'd at concentrations tested - Repeated dose toxicity, Inhalation - Ferenz, R.L. (1980) - Supporting study.

Additional information

Supporting study - Two week inhalation toxicity study: Malley, L.A. (2003):

The purpose of this study was to assess the potential subchronic toxicity of exposure to the test item in adult rats. Young adult male Crl:CD®(IGS)BR rats (10 rats/exposure concentration) were exposed to atmospheres containing 1000 ppm test item for 6 hours per day, over a 2-week period for a total of 9 exposures.

 

There were no test substance-related, toxicologically significant effects on body weight, weight gain, food consumption, food efficiency, or clinical signs of toxicity in males exposed to the test item at 1000 ppm. Exposed animals had no adverse changes in hematology, coagulation, clinical chemistry, urinalysis, or fluoride parameters. The only treatment-related, but non-adverse, change was a minimal increase in reticulocytes, without an effect on red cell mass.

There were no test substance related effects on organ weights or tissue morphology.

Test substance related changes in thyroid homeostasis were observed. Serum T3 and T4 concentrations were significantly decreased in rats following exposure. However, serum TSH was not affected. These alterations were considered to be transient effects since thyroid weight and histopathology were not affected.

Hepatic β-oxidation activity was similar to control in exposed rats.

 

The no-observed-effect level (NOEL) for this study is defined as the highest dose at which toxicologically important effects attributable to the test substance were not detected. Thus for this study, the NOEL is equivalent to the NOEL as defined by the United States Environmental Protection Agency (1985), and the no-observed-adverse effect level (NOAEL) as defined by the European Union (1994). Under the conditions of the study, the NOEL for the test item was 1000 ppm, the highest concentration tested.

 

This study was assigned a Klimisch score of 2, and has been selected as a supporting study as part of a weight-of-evidence approach to the endpoint. Based on the conditions of the study, the test item would not be classified for repeated dose toxicity, in accordance with CLP Regulation No 1272/2008 on Classification, Labelling and Packaging of Substances and Mixtures.

 

Supporting study - Subacute inhalation toxicity: Ferenz, R.L. (1980)

The study was performed to observe the effects of the test substance – BTFB on male rats following repeated inhalation exposures. The study was not performed to an OECD TG and was found not be comparable to a national or international test guideline.

Rats were exposed to either just air (Group 1), 0.1% (Group 2) or 1.0% (Group 3)  for 6 hrs/day 5 days/week for 2 weeks in glass exposure chamber. All rats were weighed and observed daily throughout the testing period with clinical laboratory measurements made following the 9^th exposure and on the 13^th day of recovery. Blood samples were taken from the rat’s tails following the 10^th exposure and the 14^th day of the recovery period. Following the 10^th exposure, 5 rats from each dose group were at random selected and sacrificed for gross and histopathological examination with the remaining rats sacrificed on day 14 of the recovery period.

 

No compound related changes (macroscopic or microscopic) were noted in any of the dose groups. Sporadic clinical observations, alterations in bodyweight, liver and spleen weight (without associted microscopic findings) and excreted fluoride levels were noted; all of which reverted to within normal limits during the recovery period. 

 

As this study was assigned a Klimisch score of 4, it is used as a supporting study as part of a weight-of-evidence approach to the endpoint and as such it is not possible to reach any conclusions on classification from this study alone.